<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <main id="app">
        <input type="button" value="+" @click="handleClick(1)">
        <span>{{num}}</span>
        <input type="button" value="-" @click="handleClick(-1)">
    </main>
    <script src="../vue.min.js"></script>
    <script>
        let vue = new Vue({
            data() {
                return {
                    num: 0
                }
            },
            methods: {
                handleClick(v) {
                    this.num += v;
                }
            }
        })
        vue.$mount("#app");

        setInterval(() => {
            vue.num ++;
            console.log(vue.$data.num);
        }, 5000);


    </script>
</body>
</html>